As an environment-friendly material, liquid crystal molecule has significant research value and great potential applications in the field of information display, organic optoelectronics and so on. Liquid crystal as a novel display material has many advantages over other counterparts, such as low power consumption, low driving voltage. The state-of-the-art liquid crystal device is characterized by its small size, light weight, long life time, large information density, no electromagnetic radiation, etc., which can adapt to almost all kinds of information displays, In recent years, the application of liquid crystal compounds has been significantly widened to all kinds of display devices, electro-optical devices, electronic components, sensors and so on. So far, many different structures have been proposed, particularly in the nematic liquid crystal field, where the nematic liquid crystal compounds have heretofore been most widely used in flat panel displays, especially in TFT-LCD products.
Most of the color display is active matrix display. TFT-LCD has been widely used in direct-view TV, large-screen projection TV, computer terminal display and some military instrument display. It is believed that TFT-LCD technology will have even broader application prospects. However, due to the limitation of the liquid crystal material itself, TFT-LCD still has some defects, such as slow response, high driving voltage, low charge retention rate and so on. Therefore, it is particularly important to research a liquid crystal compound with low viscosity and high dielectric anisotrop. In order to improve the properties of materials to adapt to new requirements, the synthesis of new liquid crystal compounds and the research on the relationship between structure and properties of liquid crystal become an important issue.
The prior art discloses a variety of liquid crystal compounds including liquid crystal compounds containing difluoromethoxy bridge. For example, in the Chinese Patent CN1717468A assigned to Merck & Co in Germany, in 2003, a liquid crystal compound containing difluoromethoxy bridge and tetrahydropyran was disclosed and elaborated, but the compounds still do not have the desired performances.